diff --git a/test/common/http/http2/codec_impl_corpus/clusterfuzz-testcase-minimized-codec_impl_fuzz_test-5728207897624576 b/test/common/http/http2/codec_impl_corpus/clusterfuzz-testcase-minimized-codec_impl_fuzz_test-5728207897624576
new file mode 100644
index 000000000000..30ada91a1a8a
--- /dev/null
+++ b/test/common/http/http2/codec_impl_corpus/clusterfuzz-testcase-minimized-codec_impl_fuzz_test-5728207897624576
@@ -0,0 +1 @@
+actions {   new_stream {     request_headers {       headers {         key: " "         value: " "       }       headers {         value: "�"       }       headers {         key: ":method"         value: "GET"       }     }   } } actions {   mutate {     buffer: 2     offset: 2     value: 2   } } actions {   quiesce_drain {   } } 
diff --git a/test/common/http/http2/codec_impl_fuzz_test.cc b/test/common/http/http2/codec_impl_fuzz_test.cc
index 0e0b6f9952dc..d17b111dfc60 100644
--- a/test/common/http/http2/codec_impl_fuzz_test.cc
+++ b/test/common/http/http2/codec_impl_fuzz_test.cc
@@ -273,9 +273,14 @@ DEFINE_PROTO_FUZZER(const test::common::http::http2::CodecImplFuzzTestCase& inpu
   // the response encoder and can complete Stream initialization.
   std::list<StreamPtr> pending_streams;
   std::list<StreamPtr> streams;
+  // For new streams when we aren't expecting one (e.g. as a result of a mutation).
+  NiceMock<MockStreamDecoder> orphan_request_decoder;
 
   ON_CALL(server_callbacks, newStream(_))
       .WillByDefault(Invoke([&](StreamEncoder& encoder) -> StreamDecoder& {
+        if (pending_streams.empty()) {
+          return orphan_request_decoder;
+        }
         auto stream_ptr = pending_streams.front()->removeFromList(pending_streams);
         Stream* const stream = stream_ptr.get();
         stream_ptr->moveIntoListBack(std::move(stream_ptr), streams);